The field of the invention relates to the entry of characters, including natural language text, into a computer, particularly a miniature handheld personal digital assistant. More specifically, it relates to a method for improving the efficiency of the entry of text and other character sequences when performed by a thumbwheel or other rotating cylinder by selecting ambiguous combinations of characters and then later disambiguating them to enter words.
As electronic devices get smaller and become increasingly powerful and capable of operation with more flexibility (by, for example, wireless connection to the World Wide Web), there is an increasing need for ways of entering information into miniature handheld devices. Such devices include personal digital assistants, two-way pagers, Web browsers, and the like. They have been described as applying to various platforms, including wristwatches, credit card-sized personal digital assistants, and larger handheld devices such as MP3 music players.
One approach that has been taken is the use of a menu and thumbwheel for navigation of a small handheld device. As is described in the U.S. patent applications cited above, such an approach can be applied to a variety of different applications (e.g., address directories, operation of a telephone). The method has been used in a variety of devices, such as the Blackberry two-way pager manufactured by Research in Motion, Ltd. of Waterloo, Ontario, Canada. The approach can even be used to enter characters, either in the form of natural language text, names, or electronic mail addresses. Typically, the thumbwheel is combined with a switch arrangement such that when the thumbwheel is pressed in a direction perpendicular to the axis of rotation of the thumbwheel, the menu item that is currently designated (highlighted) is selected. However, the entry of characters with such an approach is tedious because of the need to scroll back and forth through a long display of potential characters in order to select the desired character. Since in most systems a mechanical stepping device is used to provide a distinctive xe2x80x9cfeelxe2x80x9d (of variable resistance) of when the user has scrolled past a single item, this results in long sequences of xe2x80x9cclicksxe2x80x9d that a user must go through to locate a desired character. Since on the order of 26 to 30 or more characters are typically used for input, such entry is tedious indeed.
The thumbwheel is a very effective approach to navigation for a small handheld device, but there is a significant need for a way of entering text in a device too small for a keyboard. In particular, there is a need for a way of utilizing the thumbwheel more effectively to enter characters.
The goal of the invention disclosed here is to provide a capability of efficiently entering text using a miniature handheld device. The handheld device typically consists of a display, a thumbwheel or other rotating cylinder, a button or switch, a microprocessor for control, and a memory. The memory includes a database with a large number of words in a particular language, or names, or addresses, such as World Wide Web addresses.
In operation, a menu is displayed that prompts the user with a sequence of menu items. At any given time, one of the menu items is designated by displaying it in a manner different from the other items. This designation might be done by displaying it it reverse video, by drawing a rectangle around the item, or displaying a symbol, such as an arrow, next to the designated item. By rotating the thumbwheel in one direction or other, the designation is moved within the sequence in a particular direction. By pressing the button, the designated item is selected. Typically, a switch is incorporated within the thumbwheel assembly such that a movement of the thumbwheel sideways closes the switch, allowing the thumbwheel itself to serve as the selector button.
Alphabetic text is entered by selecting sequences of characters to form words. In the present invention, this is done in a particularly efficient manner by defining menu items such that each item contains two or more alphabetic letters. Thus, for example, the entire English A-Z alphabet might be represented by 9 menu items, with 8 of the items containing three letters each and the 9th item containing two letters.
Users enter words by selecting a sequence of menu items that each contain the desired sequence of letters. After each selection of a menu item, words are retrieved from the memory that are consistent with the sequence entered so far. These words are added to the menu and displayed. When the user sees the word that is desired, he or she moves the thumbwheel so as to designate the desired word, and presses the button to cause it to be selected. The word is then entered.
On the average, the user must enter only a few keystrokes per word to enter it. In the case of words that are not contained in the memory, once the user enters sufficient keystrokes such that no words are retrieved, or selects a special memory item to request a full alphabetic keyboard, such a full alphabetic keyboard is provided, and the word is entered with one keystroke per letter.
The system is also applicable to the entry of electronic mail and Web addresses that contain special characters, in which case xe2x80x9clettersxe2x80x9d are not just the alphabet and xe2x80x9cwordsxe2x80x9d are not necessarily natural language words or names but any sequence of characters defined in the internal dictionary of the system.
The system is applicable to a variety of applications. In one application, that of a miniature personal digital assistant, the user enters notes in text in a credit card-sized device that contains the display, thumbwheel and button, and memory. A similar arrangement might also be used in a two-way pager, to allow responses to alphanumeric pages (short messages), or the creation of short messages, or a cellular telephone.
In the case of a pager, cellular telephone, or other wireless communication device, it is possible to put the memory and associated database of words in a remote server associated with the paging or cellular base station, to minimize memory requirements in the handheld unit itself. In such a system, the selection of menu items causes them to be transmitted to the server, the memory lookup done, and the results transmitted back to the handheld unit. Such a server might also be incorporated into a device such as a cordless telephone, particularly one that had the capability of responding to and/or composing electronic mail.
In still another embodiment, the handheld device might contain only the thumbwheel, selector switch or button, and a wireless transmitter. Such an embodiment might particularly be used in a remote control for a television that used an infrared transmitter in the handheld unit. The display and memory would be contained in the television receiver, which would also include an infrared receiver. This is of particular value in a television that included Internet capabilities, including electronic mail and Web browsing. The invention would allow efficient response to and composition of electronic mail messages and Web browsing by selection of alphabetic strings representing Web site addresses.